Missing: Ground attack that can finish out game, complement revitalized passing game

Not even Michael Crabtree’s celebrated arrival nor back-to-back wins can silence all the critics of the 49ers’ offense.

“Like my dad was asking, ‘Why didn’t you run the ball better at the end of the game?’ ” coach Jim Harbaugh said Monday.

While their passing game came alive in Sunday’s 23-13 win over the St. Louis Rams, the 49ers rushing attack struggled for a third consecutive game.

Perhaps that’s why the 49ers (8-4) don’t seem in total synch entering next Sunday’s home game against the NFC West-leading Seattle Seahawks.

At least Jack Harbaugh will be around all week to help dissect the 49ers’ issues — once he’s done playing with his grandchildren Monday morning, his son quipped.

Frank Gore voiced his displeasure postgame about the rushing attack’s downward trend, as evidenced by production the past three games: 48, 31 and 42 yards. It’s his lowest three-game total since 2005, when he was a rookie backup.

Gore’s played through an ankle injury in recent weeks, but Harbaugh said that ailment hasn’t been a visible factor in games.

As usual, defenses are aware of the 49ers’ run-oriented style and stack the line of scrimmage, to which Gore said Sunday: “I don’t care. We’ve still got to get it done.”

They had to get past the Rams without their two Pro Bowl linemen: left guard Mike Iupati missed a second straight game with a sprained left knee, and left tackle Joe Staley exited in the first series with a sprained right knee.

Iupati might return to face the Seahawks but Staley likely will miss his first game since the 2010 season. Both were to undergo further medical tests Monday.

Gore averaged only 2.8 yards Sunday (15 carries, 42 yards), and the 49ers failed to eclipse the 100-yard rushing mark for a third straight game.

Once they gained a 23-6 lead, the 49ers tried to run time off the clock, but there wasn’t much running room in their final three series and they failed to produce a first down on their own.

Gore got stopped for no gain on his final carry before giving way to Anthony Dixon (eight carries, 13 yards) and Kendall Hunter (three carries, seven yards).

“Some things were muddying the run game and we didn’t get it clicking as we liked,” Harbaugh said. “They did a good job stopping the run. We countered with the pass and that was effective.”

Colin Kaepernick passed for 275 yards — his most since the season opener – and again focused on Anquan Boldin (nine receptions, 98 yards) and Vernon Davis (four catches, 82 yards, one touchdown).

“It was a good day in the passing game, and it needed to be,” Harbaugh said.

A welcome addition to that offensive mix was Crabtree, who tore his right Achilles just over six months ago. He had two receptions, but one went for 60 yards down the right sideline.

“He did a very good job,” Harbaugh said of Crabtree. “H was really into the game. He wanted the ball. He got it and made things happen.”

— Blown out the past two games against the Seahawks – both in Seattle – Harbaugh said: “We’re taking the revenge approach. Validation. We want to play well. We want to win.”

Harbaugh wasn’t about to reverse course and say the next game isn’t the biggest of the season. It always is, each week, under his reign. Now it’s Seahawks Week, and the hype is underway.

“I guess you could make the societal argument we put too much emphasis on these games,” Harbaugh said. “I don’t know about the rest of society but I know we do.”

— Harbaugh said there were “a lot of positives” for how the offensive line adjusted after Staley’s exit. Alex Boone shifted from right guard to left tackle, and Joe Looney took over at right guard, as is expected to be the case against the Seahawks. Looney got the call over Daniel Kilgore because Looney has practiced more at guard than Kilgore, their backup center, Harbaugh said.